FAQ

General Frequently Asked Questions

Table of Contents

Running Jobs

Running Jobs

How do I forward X11 traffic (for example, from TotalView) from batch jobs?

To use TotalView or other X11 applications within a batch job, the system must be able to direct the X11 traffic back to your workstation. To do this, you should first connect to ewok.ccs.ornl.gov with X11 forwarding enabled. This can be done as a configuration setting in your ssh client or can be done by adding -X to the ssh command line (ssh -X ewok.ccs.ornl.gov). Once logged on to ewok, you can run a command such as xterm or xclock to verify X11 forwarding is working. Once X11 forwarding is in place, you must tell PBS that you want to use X11 forwarding in your job. This is done with the -X option to qsub. So, to submit a job for a 64 processor debug session, you might use 

qsub -I -X -lnodes=32:ppn=2,walltime=1:00:00 -A ABC123

where ABC123 is your Project ID.

How do I launch TotalView?

In the past, there was a cusomized procedure to launch TotalView on ewok due to the version of MPI in use. Now that ewok uses OpenMPI, the procedure for TotalView is more straightforward. First, the module must be loaded: 

module load totalview

After that, TotalView is launched with a command similar to: 

totalview mpirun -a -np 16 ./a.out